Itachi. in the example of the first fight we see itachi in.
itachi and kisame vs Asuma, Kurenai, and Kakashi.
Itachi's attacks are quick and hard to notice sometime, his thought proccess is hard to keep track of it seems. not to mention he got Kakashi in his genjutsu. 1 second stretched in to 3 days in the mind.
In the start of shippuden Itachi white zetsu clone thing. sakura, kakashi, naruto and chiyo vs Itachi.
what was it 30% of his chakra and it took them quite a bit to kill the clone thing.
all in all i just don't see Choji's style being anywhere near the right stuff to take a guy like Itachi down.